Liquid-based gravity-driven etching-stop technique for controlling structure dimension
US7435355B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Oct 5, 2005 |
| Grant date | Oct 14, 2008 |
| Priority date | — |
| Expiry date | Aug 15, 2026 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB81C2201/0142
- WIPO fieldMicro-structural and nano-technology
- WIPO sectorChemistry
Abstract
A liquid-based gravity-driven etching-stop technique for controlling structure dimension is provided, where opposite etching trenches in cooperation with an etching-stop solution are used for controlling the dimension of a microstructure on the wafer level. In an embodiment, opposite trenches surrounding the microstructure are respectively etched on sides of the wafer, and the trench depth on the side of the wafer, on which the microstructure is, is equal to the design dimension of the microstructure. Contrarily, it is unnecessary to define the trench depth on the back-side of the chip. In the final step of the fabrication process, when the device is etched, such that the trenches on the sides communicate with each other to separate the microstructure from the whole wafer automatically and thereby shift from the etchant into the etching-stop solution to stop etching.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.